space - Sara Nilsen

lib/array_intersection.rb

@@ -1,3 +1,24 @@
 def intersection(list1, list2)
-  raise NotImplementedError, "Intersection not implemented"
+  longest_list = list1 #default longest list, it changes if list2 is longest than list1
+  other_list = list2
+#-------------------------------------------#
+  if list1.length < list2.length 
+    longest_list = list2
+    other_list = list1
+  end 
+#-------------------------------------------#
+  hash_table = {} #for comparing values 
+  longest_list.each do |n|
+    hash_table[n] = 1 
+  end 
+#-------------------------------------------#
+  intersection = [] #the intersection numbers 
+  other_list.each do |n|
+    if hash_table.key?(n) 
+      intersection << n
+      hash_table[n] += 1
+    end 
+  end 
+#-------------------------------------------#
+  return intersection
 end

lib/palindrome_permutation.rb

@@ -1,4 +1,35 @@
 
 def palindrome_permutation?(string)
-  raise NotImplementedError, "palindrome_permutation? not implemented"
-end
+  return true if string == ""
+
+  hash_map = Hash.new(0)
+  (string.chars).each do |s|
+    hash_map[s] += 1
+  end 
+
+  odd = 0 
+  hash_map.each_value do |v|
+    if v % 2 != 0 
+      odd += 1 
+    end 
+  end 
+  return odd > 1 ? false : true 
+end
+
+
+
+
+
+
+
+
+# if string.length % 2 == 0 #when string size is even every value should be == 2 to be permutation 
+#   hash_map.each do |l, v|
+#     if v != 2 
+#       return false 
+#     end 
+# else 
+#   hash_map.each do |l, v|
+
+#   end 
+# end 

lib/permutations.rb

@@ -1,4 +1,20 @@
 
 def permutations?(string1, string2)
-  raise NotImplementedError, "permutations? not implemented"
-end
+  return false if string1.length != string2.length 
+  first_hash = Hash.new(0)
+  (string1.chars).each do |s|
+    first_hash[s] += 1 
+  end 
+
+  puts first_hash
+  #-------------------------------------------------#
+  second_hash = Hash.new(0)
+  (string2.chars).each do |s|
+    second_hash[s] += 1
+  end 
+
+  first_hash == second_hash ? true : false 
+end
+
+#how can I check if two strings have the same number of letters
+

test/palindrome_permutation_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "palindrome_permutation?" do
+describe "palindrome_permutation?" do
   it "will work for hello" do
     expect(palindrome_permutation?("hello")).must_equal false
   end
@@ -20,4 +20,5 @@
   it "will return false for raceca" do
     expect(palindrome_permutation?("raceca")).must_equal false
   end   
+
 end

test/permutations_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "permutations?" do
+describe "permutations?" do
   it "returns true for empty string" do
     expect(permutations?("", "")).must_equal true
   end
@@ -20,4 +20,7 @@
   it "returns false if the number of a specific letter are different" do
     expect(permutations?("pizza", "piza")).must_equal false
   end
+  it "returns false for hellllllllll" do 
+    expect(permutations?("hellllllll", "hel")).must_equal false 
+  end 
 end